I took my H3 out for a much longer ride, with many hills, with the new gas, and can no longer hear the vibrating metallic sound...seems the dealer was correct in diagnosing the problem. I'll post here again when trying lower octanes, specifically 91 and 89. Thanks to all who read the original post and replied.

 

My knocking was just fixed by replacing the air filter. My K&N was over oiled from the factory and blocking air flow and coating the MAF with oil.

 

nm, the filter didnt solve it...lol.

 

Sorry to hear that. Get your tank down to empty and then fill it up with 93 octane and see if that makes a difference. Good luck.

 

91+ octane does get rid of the pinging. I wonder why my h3 cant run regular 87.

 

Just to give everyone some insite, I own a couple of two strokes from the 70's and if I don't run 93 octane they not only run like crap but sound like it too. A high pitched pinging noise. Well in my 1985 Dodge 600 convertable 2.2lt I ran 87 octane same noise so I switched and poof noise gone. The same thing happened to my 2006 H3 and then I tried 93 octane from Sunoco and no more pinging, also I run 93 octane from Mobil, I stay away from Hess because I had a piston burn out on one of my two strokes. My first one the great Yamaha RD350 1975. what a shame
http://www.youtube.com/watch?v=qYUzYNF6ZKM

 

so it seems like some owners with H3's have pinging issues on the recommended 87 octane. I was told by a mechanic that having to run a slightly higher octane is not enough to lemon a car.

 

any updates? My H3 will only stop pinging with 91 octane now.

 

10/22/09

Hey C3,

I am on my second tank of high octane (93) and the H3 continues to no longer "ping." I have not tried any lower octanes at this juncture. I'll have to try 91, but am not sure I will try 89 because of the likelihood of the noise returining, with much poorer performance, as well as exposing the engine to further risk. Similar to my first tank of high octance, the car gets better mpg and, overall, just performs much quieter, smoother, and faster.

I am in the process of writing GM about all of this and will let you know if they respond.

 

UPDATE...Im still pinging with 91 octane, just not nearly as much with 87/89